Operating voltage adjustment for aging circuits

Abstract

A system and method for updating power supply voltages due to variations from aging are described. A functional unit includes a power supply monitor capable of measuring power supply variations in a region of the functional unit. An age counter measures an age of the functional unit. A control unit notifies the power supply monitor to measure an operating voltage reference. When the control unit receives a measured operating voltage reference, the control unit determines an updated age of the region different from the current age based on the measured operating voltage reference. The control unit updates the age counter with the corresponding age, which is younger than the previous age in some cases due to the region not experiencing predicted stress and aging. The control unit is capable of determining a voltage adjustment for the operating voltage reference based on an age indicated by the age counter.

What is claimed is: 
     
       1. An apparatus comprising:
 an age tracking unit comprising circuitry configured to measure a first age of the apparatus; and 
 a control unit comprising circuitry configured to:
 receive, from a power supply monitor, an operating voltage reference measured by the power supply monitor; 
 determine a second age different from the first age of the apparatus based on the operating voltage reference; and 
 update the first age with the second age. 
 
 
     
     
       2. The apparatus as recited in  claim 1 , wherein the control unit is further configured to:
 determine an operating voltage difference between a desired operating voltage reference and the operating voltage reference measured by the power supply monitor; and 
 determine the second age of the apparatus based on the operating voltage difference. 
 
     
     
       3. The apparatus as recited in  claim 2 , wherein the apparatus further comprises circuitry configured to store mappings between voltage differences with the desired operating voltage reference and corresponding ages of the apparatus. 
     
     
       4. The apparatus as recited in  claim 3 , wherein the control unit is further configured to access the mappings with the operating voltage difference. 
     
     
       5. The apparatus as recited in  claim 2 , wherein the second age is younger than an age previously stored by the age tracking unit. 
     
     
       6. The apparatus as recited in  claim 1 , wherein the control unit is further configured to determine a voltage adjustment for the operating voltage reference based at least in part on an age indicated by the age tracking unit. 
     
     
       7. The apparatus as recited in  claim 6 , wherein the control unit is further configured to update the operating voltage reference with the voltage adjustment. 
     
     
       8. A method comprising:
 measuring, by circuitry of an age tracking unit, a first age of an integrated circuit; 
 receiving, from a power supply monitor by the circuitry of the age tracking unit, an operating voltage reference measured by the power supply monitor; 
 determining, by the circuitry of the age tracking unit, a second age different from the first age of the integrated circuit based on the operating voltage reference; and 
 updating, by the circuitry of the age tracking unit, the first age with the second age. 
 
     
     
       9. The method as recited in  claim 8 , further comprising:
 determining an operating voltage difference between a desired operating voltage reference and the operating voltage reference measured by the power supply monitor; and 
 determining the second age of the integrated circuit based on the operating voltage difference. 
 
     
     
       10. The method as recited in  claim 9 , further comprising storing mappings between voltage differences with the desired operating voltage reference and corresponding ages of the integrated circuit. 
     
     
       11. The method as recited in  claim 10 , further comprising accessing the mappings with the operating voltage difference. 
     
     
       12. The method as recited in  claim 9 , wherein the second age is younger than an age previously stored by the age tracking unit. 
     
     
       13. The method as recited in  claim 8 , further comprising determining a voltage adjustment for the operating voltage reference based at least in part on an age indicated by the age tracking unit. 
     
     
       14. The method as recited in  claim 13 , further comprising updating the operating voltage reference with the voltage adjustment. 
     
     
       15. A functional unit comprising:
 an integrated circuit; 
 a power supply monitor comprising circuitry configured to measure an operating voltage reference of the integrated circuit; and 
 an age tracking unit comprising:
 an age counter comprising circuitry configured to measure a first age of the integrated circuit; and 
 a control unit comprising circuitry configured to:
 receive the operating voltage reference from the power supply monitor; 
 determine a second age different from the first age of the integrated circuit based on the operating voltage reference; and 
 update the first age with the second age. 
 
 
 
     
     
       16. The functional unit as recited in  claim 15 , wherein the control unit is further configured to:
 determine an operating voltage difference between a desired operating voltage reference and the operating voltage reference measured by the power supply monitor; and 
 determine the second age of the integrated circuit based on the operating voltage difference. 
 
     
     
       17. The functional unit as recited in  claim 16 , wherein the age tracking unit is further configured to store mappings between voltage differences with the desired operating voltage reference and corresponding ages of the integrated circuit. 
     
     
       18. The functional unit as recited in  claim 17 , wherein the control unit is further configured to access the mappings with the operating voltage difference. 
     
     
       19. The functional unit as recited in  claim 16 , wherein the second age is younger than an age previously stored by the age tracking unit. 
     
     
       20. The functional unit as recited in  claim 15 , wherein the control unit is further configured to determine a voltage adjustment for the operating voltage reference based at least in part on an age indicated by the age counter.